Question 1

Which of the following best describes the main difference between prokaryotic and eukaryotic cells?

Accepted Answer

Eukaryotic cells contain their genetic material within a nucleus, whereas prokaryotic cells have their DNA in a nucleoid region.

Question 2

A scientist observes a cell under an electron microscope and notes the presence of a large central vacuole, chloroplasts, and a cell wall. Which type of cell is being observed?

Accepted Answer

Plant cell

Question 3

Which of the following statements about free and bound ribosomes is correct?

Accepted Answer

Bound ribosomes are attached to the endoplasmic reticulum and synthesize proteins destined for membranes or secretion.

Question 4

The 9+2 arrangement of microtubules is characteristic of which cellular structures?

Accepted Answer

Cilia and flagella

Question 5

Which component of the extracellular matrix (ECM) is primarily responsible for providing tensile strength to animal tissues?

Accepted Answer

Collagen

Question 6

According to the Fluid Mosaic Model, which statement best describes the structure of the plasma membrane?

Accepted Answer

A dynamic bilayer of phospholipids with proteins and other molecules floating within it.

Question 7

How does the presence of unsaturated fatty acids in phospholipids affect the fluidity of the cell membrane?

Accepted Answer

It increases membrane fluidity by introducing kinks that prevent tight packing.

Question 8

Which of the following substances can cross the plasma membrane without the aid of transport proteins?

Accepted Answer

Small nonpolar molecules such as $$\mathrm{O_2$}$$ and $$\mathrm{CO_2$}$$

Question 9

An animal cell is placed in a hypotonic solution. What is most likely to happen to the cell?

Accepted Answer

The cell will swell and may burst as water enters by osmosis.

Question 10

Which of the following best describes the function of the sodium-potassium pump?

Accepted Answer

It uses ATP to move $$\mathrm{Na^+}$$ out of the cell and $$\mathrm{K^+}$$ into the cell against their concentration gradients.

Question 11

Which of the following is an example of an exergonic (catabolic) reaction in human metabolism?

Accepted Answer

Breakdown of glucose during cellular respiration

Question 12

Which law of thermodynamics explains why no energy transformation is 100% efficient and some energy is always lost as heat?

Accepted Answer

Second law of thermodynamics

Question 13

What is the primary function of ATP in cellular metabolism?

Accepted Answer

To provide energy for cellular work by transferring a phosphate group

Question 14

A process is considered spontaneous if which of the following is true?

Accepted Answer

It decreases the free energy ($$\Delta G \u003c 0) of $$the system.

Question 15

Which of the following is an example of kinetic energy in a biological system?

Accepted Answer

A muscle contracting to move a limb

Question 16

An enzyme-catalyzed reaction is observed to slow down significantly when a molecule structurally similar to the substrate is added. Which type of inhibition is most likely occurring?

Accepted Answer

Competitive inhibition

Question 17

A graph shows enzyme activity peaking at pH 7 and decreasing at both lower and higher pH values. What does this indicate about the enzyme?

Accepted Answer

The enzyme has an optimal pH at 7.

Question 18

Which of the following best describes activation energy?

Accepted Answer

The energy required to initiate a chemical reaction

Question 19

A patient is given a drug that blocks gap junctions in cardiac muscle cells. What is the most likely effect?

Accepted Answer

Impaired electrical communication between cells, leading to irregular heartbeats

Question 20

A cell is observed to use a symporter to transport glucose into the cell along with sodium ions. Which type of transport is this, and what is the energy source?

Accepted Answer

Active transport; energy from the sodium gradient established by the sodium-potassium pump

Cell Structure, Membrane Function, and Metabolism: Study Guide for General Biology

Guida di studio - Domande di pratica

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